I ran the 310 in my motor like sean for a couple years ( mine was at 10.2-1 ) and in the begining had the same prob with ping. I switched to a 750 dp holley and ended up with 72 primary jets and 80 secondary jets to solve the prob. As sean mentioned there is a fair amount of over lap with that cam thus bleeding cylinder pressure so I would really doubt comp issues,,,,and if your dist is set up with a good curve and total timing ....bet its fuel.[/I]
I tell ya this ones got me stumped. I'm going to switch out the distributor with a old one just to see if there is any change. If not, then it has to be a lean carb as several have posted.
If we can back up a little here... Did you recently have the engine rebuilt and you're experiencing this pinging, or did it previously run well without the pinging and then it mysteriously just started recently? Have you at least tried dumping some octane booster in the tank to see if the problem goes away? Some people think adding booster is a "crutch", but if the reality is that if you have too high compression for the pump gas available, then that is an issue that has to be addressed. If I had to use 91 octane PLUS booster on an 8.5:1 motor, then maybe your 9.6:1 motor has too much compression for your 94 octane pump gas. Just a thought, but pouring a bottle of booster into your tank is an easier task than tearing things apart and trying to find a culprit somewhere. It at least eliminates one possible cause, then you could move on to something else.
I agree with Chris, try boosting octane, but don't do it with store bought octane boost. That stuff is a rip off, and garbage IMHO. If you look at the label, it claims to increase octane by 3-4 points, that's 3/10-4/10, not octane numbers, say from 91 to 94 octane. Adding race gas entails a much larger initial outlay of money, but it is much more effective. Adding 2 gallons of 110 race gas to 18 gallons of 93 will result in octane of 94.7. I recommend you buy some race gas. Speed shops sell it, so do racetracks. You can also buy it at some select Sunoco stations. Try adding minimal amounts to see where the ping goes away.
This engine has about 1.5 hours on it. The distributor change out is a no go. It has 30+ * of mechanical(1111984) and of course the symptoms did not change I'll add some high octane and see if there is a change, that's easy enough today a good day to be over a warm engine. it's currently 46F in south Florida
After a long day I'm in league with Sean and MHGS, lean carb all the way. That was my first thought even when I was breaking the cam in on an engine stand and had over heating issues. What I did was to change one carb for another that still does not operate properly and that really threw me off the path. Sean, I worked on this carb some time ago using Cliff's book but maybe not enough of the right things in the right places. Changing the plugs to a lower heat range did lower and even out the temp so Lightningbird is right on with that. I'll see how the temp does as winter ends for us since we are setting record lows here for the next few weeks, that 160 thermostat might still be needed.(hard to sell global warming when my bananna trees are freezing solid) I did try to add high octane fuel and the final mixture was this before I gave up: 4.5 gallons of 100 octane mixed with 7 or 8 gallons 94 does not change the ping. Thank you to all for the help. I'm my own devil sometimes and working through all the given ideas has me closer to a solution. By the way WiFi in the Garage is way cool(Christams gift from the Wife ) I'm going inside to re read Cliff's book. It will be a week or so before I get through the carb or so I'll post the fix when it's done. Thanks again Guys
I too have built 455 carbs with Cliff Ruggles book as guidance, and I have had good luck. The major issue with the 455 carbs on a 350 is the fact that the amount of air required at idle is very different due to the CID differences. On a new engine, I prefer a stock 350 carb for break in since it will be good without question. All that said, I suggest you look for a 77-81 Buick 350 Q jet which is 800 cfm and built for a 350 CID engine. The best part about these carbs is that they have an adjustable part throttle mixture (APT). I avoided these for years however now I swear by them and will not go back to a pre APT carb due to the improved throttle response and fuel economy.
glad you found the problem !! now you'll be flting before you know it .........:beer thats why I now use a holley....much easier for me to adjust.
Thought I would give a progress report on my situation. More fuel is need for this engine, much more. Heres a short version of the last two weeks: Went through the carb making sure Cliffs # 2 recipe is followed, found the main air bled was not sized correctly, idle tubes down in the channel 3/16 of an inch too much. Screwed in the apt adjustment all the way to bring the rods up out of the jets Put the carb on and it won't idle below 1000rpm,HUH! uzzled: back off the apt screw and immediately break it! By the way I was planning on ordering a screw the following day.:af: Drilled the screw and broke an easy out off in it.:ball: Start over with another throttle plate, bushings, change shafts because it was for an Olds, drill and tap the apt screw this time. Spoke with Cliff, he says it should not idle that high(must be a vacuum leak),upped the jets to 74 and thinner rods (at this moment I dont remember the size) Carb on the car, idles well and pinging is almost gone. where did the vacuum leak go?o No: must have been under the plate. Im out of adjustment on the rods so I think a little bigger jet and or smaller rods will solves this. SO its getting there!!!
Have you read this yet? it is the best q jet tuning info I have found: http://www.buickpartsdirectory.com/QJet_Tuning_Paper.doc
I agree, it is the best information. I have it printed out. A little bench cleaning of carb parts and debris and I'll go through this thing step by step. Thanks for the push in the right direction with the lack of fuel promt.
After a few weekends of tinkering I have yet to correct this problem. I ran a compression check on the left side, it was easier, to see how everything is seating. 200, 190, 190, 210. serious pressure! with this cam(ta 310 at 4* advanced) would the pressure be this high? I have 74 jets and 4Z rods(.042 taper down to 26 tips) and zero change in symptoms. I have APT control but it only lessens the problem and the runs rich during idle. Timing backed way off to 4* initial and 29 total, no vac advance connected. she's running cool with Delco R43ts and a 180 thermo, but still is just a detonation machine. The high cylinder pressure is suspect at this point. Any thoughts?
I'm running a somewhat similiar setup (See signature). Havent read anything past this first post yet, but last week I talked to Mike at TA while getting a price for a posi. According to him the cam should be at 12* initial timing, and 34-36 total. Hopefully that's all your problem is. I know on mine if I romp on it from a dead stop I can roast the tires (Which is how I obtained my current problem.. sheered my spider gears in half.) Just a side note, my car idles at 750 in park and 500 in gear. I do think I have a torque converter problem tho, looking to upgrade it to a new 2500 stall converter.
I had the TA 310 in my 350 and had no problems with detonation, I would run about 16 to 18 initial timing. That cam was a torque monster, it would fry the tires from a 10 mph roll thru second gear. It may sound stupid, but try advancing your timing to 12 initial. I've had cars detonate, rattle, ping, etc, because the timing was to far retarded. Mark
What timing set did you use? As far as I know all the replacement timning sets come with 4 degrees of advance built in except the Cloyes 3 double roller with adjustable keyways which does not. If you used a stock type timing set and advanced it 4 degrees then it is 8 degrees advanced.
My 310 cam rattles like a spray paint can as well. It takes some serious patience and time to get the thing capable of driving it on the street. I went through many springs and weights in my HEI to sort this out, but still an issue with the 310 cam.....Oh and low end torque....I must have really screwed the pooch cause the 310 cam made the motor so weak on the bottom end, it's almost as bad as a 350 chev. It does have quite a bit of mid range. It has got to be a combination of 93 octane fuel, long stroke, high cylinder pressure and high gears. Does your Skylark have stock 2.73:1 gears?
When I used a 310 cam in a 350 mine was lazy in low rpms as well.... On paper the 310 cam gives up low rpm torque to gain high rpm power.
